Taurine, or 2-aminoethanesulfonic acid, is an organic acid. It is a major constituent of bile and can be found in the lower intestine and, in small amounts, in the tissues of many animals, including humans.[1][2] Taurine is a derivative of the sulfur-containing (sulfhydryl) amino acidcysteine. Taurine is one of the few known naturally occurring sulfonic acids.

History

Taurine is named after the Latin Taurus (a cognate of the Greek ταύρος) which means bull or ox, as it was first isolated from oxbile in 1827 by German scientists Friedrich Tiedemann and Leopold Gmelin.[3] In the strict sense, it is not an amino acid, as it lacks a carboxyl group,[4] but it is often called one, even in scientific literature.[5][6][7] It does contain a sulfonate group and may be called an amino sulfonic acid. Small polypeptides have been identified which contain taurine, but to date no aminoacyl tRNA synthetase has been identified as specifically recognizing taurine and capable of incorporating it into a tRNA.[8]

Biosynthesis

Mammalian taurine synthesis occurs in the pancreas via the cysteine sulfinic acid pathway. In this pathway, the sulfhydryl group of cysteine is first oxidized to cysteine sulfinic acid by the enzyme cysteine dioxygenase. Cysteine sulfinic acid, in turn, is decarboxylated by sulfinoalanine decarboxylase to form hypotaurine. It is unclear whether hypotaurine is then spontaneously or enzymatically oxidized to yield taurine.